I stumbled on this thread, as I've inherited a TB-X606F, and I thought I could try Ubuntu Touch without buying more hardware.
@MrT10001 Thanks for the instructions. I'm wondering if you can help with the trouble I'm having. I've tried following the normal process with SP Flash Tools, but when I plug the cable in after clicking "Download", I see a red progress bar, and then I get a dialog saying "STATUS_BROM_CMD_SEND_DA_FAIL". So I thought I'd try your approach.
I'm finding that at step 3, the tablet briefly displays "META_MODE" down the bottom. Is that correct? Then at step 4, I don't see a success message, I just see the mtk_bypass tool window close. I then follow the steps to get to step 9, but then nothing happens. The SP flash tool just sits waiting.
I have had some success using the Lenovo Software Fix tool, and replacing the firmware it downloads, with one I've downloaded. When I boot the tablet after flashing this way, the build info matches the zip filename of the firmware I got, but it still says Android 10, even with the image you suggested. I wonder if that is a side effect of using this tool instead of the SP flash tool.
Does anyone have any further advice?